Method of producing ferromolybdenum and ferrotungsten



Patented Dec. 23, 1930 PAUL SCHWARZKOPF, OF REU'I'TE, AUSTRIA METHOD OIPQODU'CING FERROMOLYBDENUM AND FERROTUNGS'IEN v (I No Drawing.Application filed April 29, 1929, Serial No. 359,181, and in Germany May22, 1926.

The invention relates to a method of producing ferromolybdenum byincorporating molybdic acid with molten iron inthe presence of reducingagents. According to the 5 invention, a very homogeneous and completealloy is obtained by using a molybdic acid and in the production offerro-tungsten a tungstic acid-of very fine grain and maximum surfacedevelopment, which is obtained by vaporization from the molten ore andif desired subsequent condensation in a manner known per se.

A molybdic ortungstic acid of this kind satisfies all the preliminarychemical and physical conditions required for the production of acomplete, homogeneous, solid solution of iron and molybdenum ortungsten.

The extreme importance of the invention will be clear from the fact thatit is a question here of alloys, in which the content of molybdenum ortungsten is very small, and in which moreover, one single defectivepoint, that is to say one point insutficiently alloyed with molybdenumor tungsten, may give rise to very great practical inconvenience.

A further advantage of the invention consists in this that a molybdic ortungstic acid chosen according to the invention, is pure and uniform, sothat the amount of carbon necessarj for its reduction, can be accuratelymeasured and consequently the carbon content of the steel obtained canbe accurately adjusted. Similarly any desired percentage of molybdenumor tungsten can be reliably adjusted.

The allo obtained according to the invention di ers from those producedby other industrial methods, by its great purity and complete freedomfrom copper and sulphur. The latter is more particularly assured if useis made of a method in which the molybdic or tungstic acid is vaporizedso to speak in fractional distillation from the ore in the presence ofair or oxygen, as proposed by the same inventor for instance in his U.S. Patent No. 1,629,004. In that case in the first distillation stageall the impurities are expelled, the vaporization point of which isbelow that of molybdenum or tungsten, so that in actual practice at thevaporization temperature of molybdenum or tungsten, these metals aloneare expelled from the ore. If the ore is then maintained in a moltenstate .during the evaporating out of the molybdenum or tungsten, thereis also no possibility of any impurities being carried along bymechanical agencies.

This method of obtaining molybdic or tungstic acid is alsoparticularlyinexpensive, since use may be made both of ungraded ores and ores whichcontain natural impurities and are therefore less expensive than pureores.

Pure molybdic or tungstic acid vapors of this kind are introduced witharticular advantage directly into the iron ath, since by this meansobviously the largest possible surface is presented and the finestdistribution obtained. The invention enables such a pro- 0 cedure, sinceuse is made for alloying with I iron, of these vapors of molybdic ortungstic acid requiring no purification, and at the same time anotherknown proposal is utilized, according to which the molybdic or tungsticacid is introduced into iron which is already provided with reducingagents for this acid,

but without using in such a case the vapors of molybdic acid known perse.

What I claim is 8o 1. A method of producing ferromolybdenum orferro-tungsten consisting in evaporating molybdic acid or tungstic acidof very fine grain and maximum surface development from molten ore andintroducing the acid vapors directly into a bath of iron containing areducing agent, as set forth.

2. A method of producing ferromolybdenum or ferro-tungsten consisting ineva orating molybdic acid or tungstic acid 0 very fine grain and maximumsurface develop- -ment from molten ore, subsequently condensing the sameand introducing the said acids into a bath of iron containing a reducingagent, as set forth. :3

3. A method of producing fcrromolybdenum or ferro-tungsten consisting ineva orating molybdic acid or tungstic acid o very fine grain and maximumsurface developmentfrom molten ore and introducing the I :2: memes saidacids into a bath of iron containing reducing agents, as set forth.

s. A method of producing ferromolybdenum or ferro-tungsten consisting ineva orating molybdic acid or tungstic acid 0' very fine grain andmaximum surface development from molten ore, subsequently condensing thesame and introducing the said acids into a bath of iron containingreducing agents, as set forth.

In testimony whereof I have signed my name to this specification.

PAUL SCHWARZKOPF.

